The basic idea is this: anything running on your iPhone uses up the battery, so we’re going to go into the Settings app and turn some things down, and turn others off altogether. The more you turn off, the longer your batter will last — but of course the less you’ll be able to do. It’s a balancing act but one that can help you squeeze out a little extra juice when you really need it.
Set Auto-Lock to 1 minute
Turn off any extra sounds, like keyboard clicks
Turn off the iPod EQ
Use headphones instead of the speaker if you have to listen to audio or music
Turn down the screen brightness
Turn off Bluetooth when not using it
Turn off Wi-Fi when not using it
Turn off 3G when not using it
Turn off Location Services when not using them
Turn off Push Notifications
Set all email, calendar, and contacts accounts to “Fetch” (turn off Push)
Double-click the Home Button to activate the multitasking dock, hold your finger on an app to enter “jiggly” mode, and kill any apps that might be running in the background, especially VoIP (like Skype), streaming audio (like Pandora), or navigation (like TomTom).
If you’re really desperate, put your iPhone in Airplane Mode and save the radios for when you need them (works really well). If you’re really desperate, you can also turn your iPhone completely off until you need it (it will still use a tiny amount of power but far, far less than anything else).
